Download MendeleySac1-Vps74 structure reveals a mechanism to terminate phosphoinositide signaling in the Golgi apparatus.
Cai, Y., Deng, Y., Horenkamp, F., Reinisch, K.M., Burd, C.G.(2014) J Cell Biol 206: 485-491
- PubMed: 25113029
- DOI: https://doi.org/10.1083/jcb.201404041
- Primary Citation of Related Structures:
4TU3 - PubMed Abstract:
Sac1 is a phosphoinositide phosphatase of the endoplasmic reticulum and Golgi apparatus that controls organelle membrane composition principally via regulation of phosphatidylinositol 4-phosphate signaling. We present a characterization of the structure of the N-terminal portion of yeast Sac1, containing the conserved Sac1 homology domain, in complex with Vps74, a phosphatidylinositol 4-kinase effector and the orthologue of human GOLPH3. The interface involves the N-terminal subdomain of the Sac1 homology domain, within which mutations in the related Sac3/Fig4 phosphatase have been linked to Charcot-Marie-Tooth disorder CMT4J and amyotrophic lateral sclerosis. Disruption of the Sac1-Vps74 interface results in a broader distribution of phosphatidylinositol 4-phosphate within the Golgi apparatus and failure to maintain residence of a medial Golgi mannosyltransferase. The analysis prompts a revision of the membrane-docking mechanism for GOLPH3 family proteins and reveals how an effector of phosphoinositide signaling serves a dual function in signal termination.
Organizational Affiliation:
Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520.
